Tuesday, August 15, 2017

MMAC Free Flight Contest North Branch

Not much time since the free flight Nats in Muncie and I made my way to the Minnesota free flight contest near North Branch Minnesota. I had been there before this year which started out with rain, this contest ended with rain. It was dark and the grass very damp but the wind was light and the temperature cool. More important I had fun and did not lose any airplanes.

Dave Edmonson Launching

To start out with to get quick flights in to check the wind drift I flew my e36 Super Pearl, just like at the Nats it flew really well, I also flew my e20 Sky Demon which quit working after a couple of flights because of the wet grass and the electronics.  

Jetstream  Before Wing Recover

Jetstream in Flight

Tom's Glider

Dave Edmonson was flying his towline when I arrived and had his launcher set up, so I tried my Jetstream towline. The turn seemed to have changed since the Nats and I had trouble getting launched from the launcher in the low wind. Another MMAC member Tom helped me launch and I decided to make some official flights. I had most of the line out but there was a snarl in the reel near the end so did not have it all. The glider towed good but I had to run really fast to keep it going up, it came off the line nice and made some big circles around the field. It did not encounter any lift and was down all three flights in around 43 seconds. I was happy that it launched and did not spiral into the ground.

Wilbur on 200 Turns
Winder Binds at Times

Next I took out my Wilbur rubber model, the one that spent time in the corn at Muncie. Saturday I made some really short test flights from a small field with 100 turns and it required more right turn which I added through rudder. For the first flight on Sunday I used 200 turns, it circled up steep but not stalling and glided with just a hint of a stall. Thought that looked good so tried to make a contest flight with 400 turns. As I launched it went straight up, hung on the prop, slid backwards and tried to recover just as it landed.  I added tip weight for more turn and tried again with the remaining turns and same result. Had trouble with my Stanley winder binding up again too so I put the model away.
I worked on getting a catapult glider in trim to enter a little later. 

Basic Yeller Landing by the Car

Then I decided I wanted to fly my Basic Yeller PeeWee 30 model again because running a glow engine is allowed here. It started pretty easily and I got the fuse lit with my new plasma lighter easily.  It climbed really high, people were impressed. The glide was slow but still has a hint of a stall. On the last flight it landed next to my car, a good thing as it was starting to rain.

It would be good to go to a contest with aircraft that were completely trimmed out, but reality is that closer to me there are no large fields to fly from.  I would like to have more time to talk to people and watch their flying too, I will try harder in the future.

Bill Kuhl

Related Blog Posts


Thursday, August 10, 2017

Dynomite, Jetstream, Retro Gnome, and CO2 Nats 2017

I am finishing up with brief descriptions of flying these planes at 2017 Nats.  The start of the hand launch event started with drizzle and rain. This year I had barely flown my Dynomite DLG at all, concentrating mainly on flying e36 planes at home. I did a few test flights before the event but that was about it, there was a small repair to do before contest flights. I wanted to fly even in drizzle in case it was an all-day rain, which it wasn’t. On the two official launches I released too late and had bad height with the glider down in 20 seconds. I tried another launch and the glider came apart in the air, it was way beyond a field repair. 

Dynomite Blew Up

Paul Bradley and Don DeLoach launched my Jetstream glider for me a few times and after adjusting the turn it appears to tow well and transition into a glide. If the glider went left in the glide it seems to tighten up in the turn. More work is needed but I really need a launching stooge so I can spend more time launching without having to take another flier away from their flying. Classic Towline was held on Friday and I left that day so did not fly it in competition. I really need more time working with the glider before contest flights.

Jetstream After Completition
On a couple of days I flew my hi-start Retro Gnome glider, at least I could fly this without assistance from anyone. The tall grass was a pain with snagging the line but it made for softer crashes.  It appears you really need to launch straight into the wind because if the glider gets a little crosswind the hi-start will pull it into the ground. One flight it flew for a fair amount of time and landed in a crushed rock parking lot. Somehow I spaced out when the contest was held and never entered.

Retro Gnome Hi-start Glider

I brought along the CO2 powered plane I had been flying this year in hopes I could talk to people with some experience in CO2. The problem I am having is filling the tank to get a consistent run; I usually get one flight out of cartridge and waste the rest. Saturday evening I had a couple of fair flights but not anywhere as long as some flights I have had. I talked to Ralph Bradley about CO2 and learned much, such as there are cartridge holders for the longer CO2 cartridges. 

My CO2 Powered Plane
Saturday Evening Flight

On another day at least a couple of people tried to fill the CO2 for me and they did not have good luck either. This plane has a fuse DT so between fiddling with lighting the DT and getting a good fill on the CO2 it was frustrating.  On one flight the motor started backwards and I launched it. For a short time it did fly around wildly backwards, Larry Davidson got a kick out of that. I had brought a limited number of CO2 cartridges so I gave up when all were used up.

Bill Kuhl

Related Links



Wednesday, August 9, 2017

Polecat X P30 at 2017 Nats

Most all of the testing of the Polecat X P30 model was done at the 2017 Nats mainly because of not a large enough flying site close to home.  I had flown it several times on smaller sites using only hand winds but as someone pointed out you cannot really see what it will do when a large number of turns are used. In my case the Polecat flew just fine as I increased the turns, this is one plane that pretty much flew with no trim adjustments needed.  If you read my build report, you know I was trying a lot of new things with this model; covering with Mylar, using tiny carbon strips, rolling a balsa fuselage, and trying the pop-off wing DT using an electronic timer.

Polecat X in Flight

Polecat X

Any concern I had about the plane landing too hard because the wing is separated from the fuselage were unfounded. The wing spins so fast on the line it slows the plane way down when coming down. One time I forgot to close one of the swivels and the wing came off the line; that did slight damage to the fuselage tube. Another time I must have had the line under the stab and it damaged the rear of the stab when the wing separated. 

Mistake with Routing Line

At first I was a little frustrated with the wing hold down method as with a slight breeze the wing would come off. I expressed my frustration to Jerry Murphy and he said I needed more tension on the DT line. I told him I was concerned with the tiny DT servo not functioning if too much tension. He gently increased the tension making sure the servo would still operate. Now the wing would stay on in a reasonable wind.

After Typical DT Landing

Selman e20 DT Timer
I never did get up to the 2000 turns possible with the rubber motor made up of 3/32” strands but did get up to 1400. As designed it climbs slowly but the propeller spins a long time. The last flights I made on the Muncie field had the plane drifting a long ways for chasing on foot. I did have my tracker on it after losing the Wilbur for a few days. Luckily I did not need the tracker to find the model but I did find out that it doesn’t go through even small hills. As high as I could hold the antenna I could not get a signal until I got on top of the small hill.

Looking forward to flying the Polecat X more, I did not fly in competition as it was windy the last day and I left for home.  The weight of the electronic DT with battery no doubt is a few grams, maybe not suitable for competition. For me at this point it is more important to be able to bring the plane down at a precise time to keep it on a smaller field.

Bill Kuhl

Related Links

 http://www.pearlfreeflight.com/Buy.html  Pearl Free Flight website to Purchase Polecat X

Monday, August 7, 2017

E20 & E36 at the Free Flight Nats

After coming to the 2016 with my e36 Super Pearl that had some issues resulting in no official flight, this year I came with two e36 models and an e20. Before the competition started I flew the Starduster e36 I had built over the winter but a bad launch damaged the wing. I repaired it but just couldn’t seem to get consistent flights, no doubt there are weak spots causing inconsistent flight patterns. The BMJR e20 Sky Demon flew pretty well when launched correctly.

Super Pearl e36 2017 Nats

Super Pearl e36 Climb

After last years Nats I discovered on the Super Pearl there was a weak spot in a dihedral joint and the stab was not as rigid as it should have been. The problem of diving when gliding to the right went away and I had some good flights.  For this year I covered the pylon with fiberglass cloth, improved the DT system, and replaced the vertical fin with a two-layer fin that was straight. Test flights looked really good; I was ready for the contest.

Flight at Muncie

Tuesday evening was the non-official e20 event.  My plane was the only one that wasn’t a pod and boom design, it has a full fuselage. The first flight I cheated myself in not having the DT set long enough, flying it earlier I had a hard time finding the tiny plane in the tall grass and had set a shorter DT time.  Increasing the DT time my plane did pretty well for what it is but came in 7th out of 11 entries. I was so busy flying I did not take any pictures, earlier I took pictures of Paul Bradley’s E20, Ralph Bradley won the event with a similar plane.

BMJR Sky Demon e20

Paul Bradley e20

Wednesday was the official e36 event, I knew there would be a lot of entries and most would have more powerful motors than the 1806N motor I was using.  Picking the weather conditions for me is rather like my stock market theory, if it looks like conditions are pretty good I fly early because I am afraid it will get windy later. In the market I seem to cash in when ahead but could have done better if stayed in longer but sometimes I have dodged a bullet.

e36 Starduster after Many Repairs

My three flights in e36 looked good, the E36 Pearl climbed in a steep spiral to the right and transitioned beautifully. The glide was really slow. On the last flight it encountered lift and made an easy max, at least it came down by DT after 2 minutes. That was really cool, I felt like now I was on the way to try for greater performance.

Bill Kuhl

Related Links

http://www.pearlfreeflight.com/Buy.html  Pearl Free Flight Super Pearl e36
http://www.texastimers.com/  eMax electronic timer
http://www.bmjrmodels.com/sky-demon  BMJR Sky Demon
http://scienceguyorg.blogspot.com/2016/08/flying-my-e36-at-2016-nats.html  - e36 at 2016 Nats
http://scienceguyorg.blogspot.com/2016/10/making-progress-in-e36.html - my learning process in e36
http://scienceguyorg.blogspot.com/2016/12/sky-demon-e20-build-report.html  - BMR Sky Demon
http://scienceguyorg.blogspot.com/2017/01/starduster-bmjr-e36-build-report.html - e36 Starduster

Friday, August 4, 2017

Basic Yeller PeeWee 30 Free Flight

How I ended up building a PeeWee 30 glow powered free flight model came about in a rather roundabout way. I was ordering a used book from NFFS on power models and noticed a book on PeeWee 30 event and purchased that too. PeeWee 30 models are powered by a Cox PeeWee .020 glow engine and limited to a 30” maximum wingspan. 

Basic Yeller

 About that time I was ordering a Witch Hawk 500 kit from BMJR Models and I thought there was a discount for a second model, I added on a Sniffer kit also which qualifies for this class but not the most competitive design. When the Sniffer arrived I decided to build it electric powered with RC for DT function.  Yet I still wanted to build a glow powered PeeWee 30 so selected the Basic Yeller design which had to be built from plans.

Building from plans instead of a laser-cut kit seemed like a lot of work but it went pretty well. The structure of this plane is really thought out well with many diagonal pieces in the wing and stab. Finished airplane came out exactly at the minimum weight of 100 grams. For most of the adhesive I tried using Titebond glue using a glue syringe, this worked pretty well for more accurately applying the glue compared to squeezing it out of a tube of Duco. 

This was the first glow engine model for me in a long time; I did have a couple of PeeWee engines but obtained one with hole for fuel line drilled in the tank. Engine run time is controlled by using an eye dropper fuel tank, getting consistent run time I need to work on. DT system is a fuse which I have little experience with. Cleaning up the mess afterwards was not something I had missed but it isn’t too bad.

When the model was pretty much complete I gave it some test glides from a small hill, the glide looked really good.  I started the engine a few times and tested the fuse DT; I need more experience lighting a fuse. At the first Minnesota free flight contest, I decided to start it up and give it a launch. Darn it climbed out nicely, the glide stalled pretty bad.

There is a PeeWee30 event on the last day of the Nats but I thought I better do some test flights before the day of the event. I shimmed wing on the side to create a tilt for glide, this appeared to help the glide but might not be perfect yet. On the first runs I used 10% nitro but I switched to 25%, this helped the climb and the motor was far from lean.  It climbed to a good height on first test flights, and took a long time coming down. The first good flight went half way across the field and landed next to the blacktop, when I retrieved it the stab was down. For the next flight I made darn sure the fuse was lit before launching. What little wind there was had switched and it was gliding towards the RC soaring area. Just at the edge of where they were flying it came down by DT. 

Flying at Muncie

Contest day started out windy so I decided to head for home. I was satisfied that I had built the model pretty well and the trim was close to right. 

Bill Kuhl

Wednesday, August 2, 2017

Wilbur Rubber Model at the 2017 Nats

Last week I attended my second outdoor free flight contest at the International Aeromodeling Center in Muncie, Indiana, the first time was in 2016.  After my first free flight Nats, I was so pumped up I built a bunch of free flight models, probably too many to allow for proper testing. Trying to decide how to split up my blog posts on the 2017 Nat’s I decided to describe what happened with each model in a separate post, starting with the old time rubber model the Wilbur.

Wilbur Found in the Corn

After the 2016 Nats and meeting Jim O’Reilly in person I decided I would try to build a rubber model larger than a p30, the largest rubber model I had built. Through some communications by email with Jim I decided to purchase the Wilbur plan and the Bob Holman short-kit from Jim’s business.  There were many new challenges; building a fuselage that was all diagonal braces, building a folding propeller, and fitting in an electronic band burner DT. By ordering a propeller blank through Volare Products much of the propeller work was completed.

Folding Propeller

Up to this point I had never braided a rubber motor, I attempted to braid a motor by watching a Youtube video. The resulting motor I created shook something terrible when I made test flights from hand winds because the rubber strands were uneven.  Jim and Chuck Powell gave me a demonstration on how to braid a motor the day before flying started at the Nats. Chuck had created some loops for me that I shoved in a box.

Test Gliding Wilbur

In the afternoon of the first day of competition I took out the rubber loops only to find one end of the rubber was so knotted it was unreal. I tried to straighten out the mess but gave up; this rubber could be cut up later for small models. From what I had learned I created a new motor and that went pretty well. I tried several flights from hand winds and the rubber unwound smoothly and the plane appeared to be in trim.

Knotted Mess of Rubber

Next I got out my winder and put in maybe 100 turns, this took the plane up a little higher so I could get a better idea what the glide looked like. I was happy that it flew as well as it did with no trim adjustments. It was getting close to 5 pm and I was going to put it away but thought no, one more flight. Like a fool I did not put a tracker on it, something I had just purchased used from Lee Campbell.

Walston Tracker

This time I wound in 200 turns, enough to take the model up to maybe 50 feet. The propeller folded and the model just kept gliding in a direction towards a cornfield, not the direction models had been drifting. I ran closer but could not keep up, why didn’t it land? No doubt it was in lift but having flown more RC sailplane than free flight I am not used to seeing a model stay up in lift so close to the ground. 

Wilbur Framework

From a distance it appeared the plane just barely went into the corn, but how do you know.  I looked for it for maybe 30 minutes or so and gave up. My name and phone number were on it and I thought maybe someone else would come across it looking for their plane. 

 Everything I flew after that except for my e20 had my tracker on it. Thursday afternoon I thought I would try to find it one more time.  I walked the area I thought I saw it last and darn if within about 10 minutes of looking I spotted it on top of a cornstalk. Having rained that morning the wing was warped but otherwise it was in perfect condition. I couldn’t stop smiling, Chuck Powell took my picture.

Warped Wing

There were much more dramatic airplane retrieval stories though out the week than mine. I understand Bob Hanford had a plane that failed to DT fly for 30 minutes into town and he was able to retrieve it. Sadly Mark Vancil lost a new Gollywock rubber model after watching it fly for over 6 minutes, some models landed in newly formed ponds on the field. Risk of losing a model is a part of free flight and a good reason to keep building more.

Bill Kuhl

Related Links

P. Visser's "Wilbur" Nostalgia Mulvihill per Zaic '53    Item ID  NOSR9 

http://volareproducts.com/   Propeller Blanks

http://www.faimodelsupply.com/  FAI Model Supply - bearings and bushings

http://www.starlink-flitetech.com/bbt-timers Band Burner

Friday, July 21, 2017

College for Kids 2017 - Wound Up

Another year of College for Kids at Winona State University is completed. Even teaching to smaller class size it was challenging. Building anything is not something that comes easy for many kids and probably many adults. Someone that was an educator for many years and works now with model aviation education told me once it is the spatial intelligence that many kids have a problem with. My father was a master at that and could envision complicated machines in his head such as 4-wheel drive tractors and then build them with no plans.  I would like to think I have a little of his ability.

Doc Fizzix Mousetrap Car

Again this year students built the Doc Fizzix mousetrap cars instead of the design I had on my website, which saved me a ton of work getting ready. I think I am getting better at teaching with this kit and the cars went together fairly well this year. On the same day as building the mousetrap cars students built the framework for the Mountain Lion Mark II balsa and tissue model airplane which was new this year. This is a more delicate model plane than my foam and balsa model FFF. There was less breakage than I imagined but I had cautioned the students several times about the delicate parts.

Mountain Lion Mk II

The final day the Mountain Lion kits were finished up. With the first group of students I had forgot to caution the students that although both wing halves were identical, you have to cover with tissue on top side only of each wing panel. On a couple of the planes they had to rip off covering on one wing half and recover.  Teaching the construction of this plane should go better the next time. With experience you learn what the more difficult parts are and adjust your explanations accordingly.

Add caption

The local newspaper, Winona Daily News did a very nice story on College for Kids this year including much about my class, I have provided the link. Also a student had left her Mountain Lion airplane and I flew it at local park, it flew every bit as well as the one I had constructed.

Bill Kuhl

Winona State College for Kids Link


Related Vendors

http://www.docfizzix.com  - using mousetrap car kits from Doc Fizzix

http://www.lasercutplanes.com/ - Mountain Lion Mk II and other kits

Winona Daily News Article

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